linux/include/asm-x86/vdso.h
Jeremy Fitzhardinge 6a52e4b1cd x86_64: further cleanup of 32-bit compat syscall mechanisms
AMD only supports "syscall" from 32-bit compat usermode.
Intel and Centaur(?) only support "sysenter" from 32-bit compat usermode.

Set the X86 feature bits accordingly, and set up the vdso in
accordance with those bits.  On the offchance we run on in a 64-bit
environment which supports neither syscall nor sysenter from 32-bit
mode, then fall back to the int $0x80 vdso.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-16 11:08:27 +02:00

48 lines
1.3 KiB
C

#ifndef _ASM_X86_VDSO_H
#define _ASM_X86_VDSO_H 1
#ifdef CONFIG_X86_64
extern const char VDSO64_PRELINK[];
/*
* Given a pointer to the vDSO image, find the pointer to VDSO64_name
* as that symbol is defined in the vDSO sources or linker script.
*/
#define VDSO64_SYMBOL(base, name) \
({ \
extern const char VDSO64_##name[]; \
(void *)(VDSO64_##name - VDSO64_PRELINK + (unsigned long)(base)); \
})
#endif
#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
extern const char VDSO32_PRELINK[];
/*
* Given a pointer to the vDSO image, find the pointer to VDSO32_name
* as that symbol is defined in the vDSO sources or linker script.
*/
#define VDSO32_SYMBOL(base, name) \
({ \
extern const char VDSO32_##name[]; \
(void *)(VDSO32_##name - VDSO32_PRELINK + (unsigned long)(base)); \
})
#endif
/*
* These symbols are defined with the addresses in the vsyscall page.
* See vsyscall-sigreturn.S.
*/
extern void __user __kernel_sigreturn;
extern void __user __kernel_rt_sigreturn;
/*
* These symbols are defined by vdso32.S to mark the bounds
* of the ELF DSO images included therein.
*/
extern const char vdso32_int80_start, vdso32_int80_end;
extern const char vdso32_syscall_start, vdso32_syscall_end;
extern const char vdso32_sysenter_start, vdso32_sysenter_end;
#endif /* asm-x86/vdso.h */